For example, a broadcast station has fixed-point observation cameras, such as so-called weather cameras, installed at various locations. A video of each fixed-point observation camera is transmitted to a data center by streaming delivery, and is accumulated in the data center. For example, in the event of natural disasters such as earthquakes, tsunamis and eruptions, or at the time of investigation of a crime or the like, VOD (Video on Demand) distribution is performed by reading video data of a specified time from video data, of a fixed-point observation camera, accumulated in the data center. In many cases, reliability of video data of a fixed-point observation camera is secured by the data being held by a plurality of storage devices according to a redundant configuration of the system.
FIG. 1 is a diagram illustrating an example of a video data accumulation system. A video data accumulation system 100 is an example where a redundant configuration is adopted by a data center, and where video data is held by different storage devices. The video data accumulation system 100 includes a data center 61 and an encoder 50 that are connected over the Internet. For example, the encoder 50 is a fixed-point observation camera. For example, the encoder 50 encodes video data by MPEG (Moving Picture Experts Group), and successively transmits the data to the data center 61 by using RTP (Real-time Transport Protocol). The RTP is a protocol for transmitting audio and video in a real time. The flow of data that is streamed from a predetermined source to a predetermined destination is called a stream.
The data center 61 is a data center of a broadcast station, for example. The data center 61 includes a relay server 70, an accumulation server A, an accumulation server B, a file server A, and a file server B. Additionally, in the case of not distinguishing between the accumulation servers A and B, they will be written as “accumulation server(s) 1”. In the case of not distinguishing between the file servers A and B, they will be written as “file server(s) 2”. The accumulation server A and the accumulation server B are servers installed at different locations. The accumulation servers A and B may use a common file server 2 or different file servers 2.
According to the video data accumulation system 100 illustrated in FIG. 1, there is one path between the encoder 50 and the data center 61, and video data is transmitted along this one path. The video data is duplicated, in the data center 61, by the relay server 70, and is transferred to each of the accumulation servers A and B. The accumulation servers A and B accumulate, as files, the video data in the file servers A and B, respectively. Files of the video data received by the accumulation servers A and B are illustrated in FIG. 1 as files A and B.
FIG. 2 is a diagram illustrating an example of the video data accumulation system. A video data accumulation system 200 is a configuration where the paths from an encoder to a data center and accumulation servers are made redundant.
The video data accumulation system 200 includes a data center 62 and an encoder 50 that are connected over the Internet. The data center 62 includes an accumulation server A and an accumulation server B. The accumulation servers A and B are installed at different locations.
According to the video data accumulation system 200, the encoder 50 has different paths for the accumulation servers A and B, and transmits the same video data along the respective paths. The accumulation servers A and B accumulate the received video data in the file servers A and B as files A and B, respectively.